1. Field of the Invention
The present invention is directed to a system for annotating video or still images.
2. Description of the Related Art
The remarkable, often astonishing, physical skills and feats of great athletes draw millions of people every day to follow sports. In particular, the amount of people watching sports on television and the amount of advertising revenue received for televised sports has increased significantly. To satisfy the increased demand for televised sports, broadcasters have deployed a varied repertoire of technologies to highlight to viewers these exciting events. For example, broadcasters have started adding graphical enhancements to the video of the sporting events. Examples of graphic enhancements have included highlighting moving objects, highlighting portions of a playing field (e.g. first down line), adding virtual advertisements and adding of other graphics to the video of the event.
One enhancement that has been particularly popular has been the telestrator system, which is a system that allows an operator to draw on live or stored video. Examples of drawing on the live or stored video include the operator drawing lines, circles or other shapes, or symbols. While the operator draws the lines, the operator will discuss events, objects or people significant to the drawing. One example of a successful use of telestrator systems is during the broadcast of American football games. An announcer may draw on an image to show a player out of position, a loose ball, a player offsides, etc. Various telestrator systems allow the broadcaster to control the width, color, texture and shadowing of any drawing. Additionally, some systems allow for the inclusion of automatic shapes and animated icons with the video.
Prior art telestrator systems typically include a video monitor with a touch screen or digitizing table. In communication with both the touch screen and the monitor is a processor. The processor receives input from the touch screen and is responsible for adding to the video whatever is drawn by the user.
While the prior art telestrator systems have been successful, they can be improved to further enhance viewer enjoyment of the event. For example, the prior art telestrator systems only work well when drawing on still images from a video. If the video images move, the camera moves or the broadcaster switches to a different camera after the operator draws on the video, then the drawing from the operator has to be removed from the video or the drawing will be out of place. This is because the drawing is added to the video by overlaying it on top of the current frame being broadcast. Even if the images or the camera move, the position of the drawing in the frame will not move and will remain in the same position in subsequent frames of video. For example, FIG. 1 depicts a frame of video 10. Frame 10 shows a portion of an American football field including the 15 yard line and the 20 yard line. In this example, the operator of the prior art telestrator system has drawn an arrow 12 to indicate where a player was running, direction of movement, etc. If the camera providing the video were to pan so that the camera points to a different portion of the football field, the portion of the football field in the video would change but the position of arrow 12 in the frame would not. For example, FIG. 2 shows a second frame 14 from the prior art telestrator system. Frame 14 differs from frame 10 because the camera has panned to show the 25 yard line. Although the location of the portions of the field have moved between frame 10 and frame 14, the position of arrow 12 remains in the exact same position in frames 10 and 14. If the operator originally was drawing arrow 12 to show the path a player ran on the field, when frame 14 is depicted arrow 12 will no longer show the actual path. That is, in frame 10 arrow 12 shows a path across the 15 yard line stopping just before the 20 yard line. On the other hand, in frame 14 arrow 12 shows a path not crossing the 15 yard line, but rather crossing the 20 yard line. Thus, arrow 12 is no longer an accurate representation of what the operator intended to draw.
A further enhancement that could be made to prior art telestrator systems is to improve the quality of the illustration. For example, an operator may have sloppy penmanship and, thus, the lines or shapes drawn could appear too sloppy or not pleasing to the viewer. Alternatively, when prior art telestrator operators draw over video, whatever they draw tends to be placed on top of and obscuring the players or objects. Therefore, there is a need to improve the prior art telestrator systems.